Portable electronic devices, such as portable computers, personal digital assistants (PDAs), and cellular telephones, typically include a battery to provide power to the portable device. In order to maximize battery life and avoid loss of data, most portable electronic devices include power management techniques. Battery life is typically addressed by reducing the power consumption of a device when the device is not used for a period of time, such as shutting down the device or entering a low power consumption state (e.g., a sleep mode). Further, portable electronic device that include a memory, such as a random access memory (RAM), must retain some minimum battery power level to preserve the stored data. Thus; to avoid loss of data, such electronic devices typically perform a controlled shut down before a certain minimum battery level is reached.
Power management techniques thus reduce power consumption at the expense of one or more of system specifications, such as speed, noise, battery life or processing speed. Most power management techniques only define active and power saving states for network devices based on network activity and device usage. For example, when there is no traffic on both the receive and transmit paths for a predefined minimum time period, the power management software will typically shut down the device or enter a low power consumption state.
A need therefore exists for a method and apparatus for providing improved power management techniques that reduce power consumption by selecting a transmission mode with reduced power consumption as the battery level gets lower.